U65Fe30Al5非晶合金的納米壓痕蠕變行為研究U65Fe30Al5非晶合金的納米壓痕蠕變行為研究NANOINDENTATION CREEP BEHAVIOR OF U65Fe30Al5 AMORPHOUS ALLOY 針對(duì)U65Fe30Al5新型非晶合金，在室溫下利用納米壓痕測(cè)試技術(shù)研究了峰值載荷和加載速率對(duì)其蠕變行為的影響規(guī)律。結(jié)果表明，隨著峰值載荷和加載速率的增加，在相同蠕變時(shí)間內(nèi)，蠕變位移呈增大趨勢(shì)，但當(dāng)加載速率高于特定閾值時(shí)，蠕變位移不再增大。通過(guò)蠕變經(jīng)驗(yàn)公式擬合發(fā)現(xiàn)，蠕變過(guò)程的應(yīng)力指數(shù)隨峰值載荷的增加不斷變大，但隨加載速率的增加先減小后基本恒定。與常規(guī)晶態(tài)合金相比，U65Fe30Al5非晶合金具有更大的應(yīng)力指數(shù)，這反映出后者內(nèi)部結(jié)構(gòu)中富含自由體積. Uranium is a valuable nuclear fuel material, but this application is unavoidably handicapped by the easy creep behavior of the metal that is caused by the combination of stress and irradiation in nuclear reactor. Uranium-based amorphous alloys, as a kind of potential new materials in the nuclear industry, would be challenged by this issue when used in such situation. However, creep properties of these materials have not been reported in the previous studies. In order to preliminarily investigate the creep phenomenon derived from stress function, this work is performed to study the ambient creep behavior of a new amorphous alloy U65Fe30Al5. This alloy was tested by using a nanoindentation technique under different peak loads and loading rates. The results indicate that the creep displacement gradually increases with either the peak load or the loading rate in equal creeping time, but this tendency vanishes when exceeding a critical loading rate. The fitting based on an empirical creep equation reveals that the stress exponent of the alloy ascends when raising the peak load, and firstly declines with the loading rate and then keeps constant above the critical rate. Compared with conventional crystalline alloys, the U-Co-Al alloy shows a larger stress exponent, reflecting the possible existence of rich free volume in the amorphous alloy. 全文下載：http://pan.baidu.com/s/1bo4xaFl
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